rc git: Improve git-log highlighters
rc git: Improve git-log highlighters

Adds support for highlighting git-log(1) output with the ‘--graph’
and ‘--pretty=oneline’ options.

danr/kakoune,casimir/kakoune,occivink/kakoune,jkonecny12/kakoune,casimir/kakoune,mawww/kakoune,lenormf/kakoune,danr/kakoune,occivink/kakoune,jkonecny12/kakoune,lenormf/kakoune,Somasis/kakoune,alexherbo2/kakoune,danr/kakoune,lenormf/kakoune,mawww/kakoune,alexherbo2/kakoune,lenormf/kakoune,occivink/kakoune,occivink/kakoune,casimir/kakoune,mawww/kakoune,danr/kakoune,jkonecny12/kakoune,Somasis/kakoune,casimir/kakoune,jkonecny12/kakoune,Somasis/kakoune,Somasis/kakoune,mawww/kakoune,alexherbo2/kakoune,alexherbo2/kakoune